(1) Field of the Invention
The present invention relates to a tool designed to facilitate the insertion of a printed circuit card into a holder therefore as well as the subsequent extraction from the holder.
(2) Description of the Prior Art
Today, printed circuit cards are frequently assembled in a holder rack having the shape of an open topped box whose side walls form tracks for the guidance of cards sent to and out of their assembled position. Terminal tabs on a base strip or block of each board fit into a socket having co-acting contacts to complete a connection to an external circuit. In practice, the track forming side walls may be horizontally disposed, with the contact bearing sockets arranged on the upright rear wall.
The placement of such printed circuit cards and their holder is a somewhat delicate operation since in the last phase an additional thrust must be exerted in order to interfit the co-acting connector pairs. In view of the great frictional resistance, attempts to insert a card with bare hands may cause injury to the operator whose fingers could be cut by the exposed front edges of the board when applying pressure thereto. It is also important to hold the card properly aligned with its guide channels in order to avoid bending stresses which could damage the printed circuits. Extracting the inserted card again poses problems since the abrupt reduction of frictional resistance upon disengagement of the connectors may lead to an accelerated withdrawal motion deviating from the straight linearity. These basic problems are perceptively increased as the printed circuit cards become larger which substantially increase the insertion and extraction force required to properly seat the cards.
Accordingly, a tool is usually required to properly seat these cards. The tool must be compact, simple to operate as well as human engineered to be comfortably operated by either hand. Many cards presently on the market have extraction and insertion mechanisms built on the printed circuit cards. This approach increases the individual card cost and therefore a separate tool is a more economical approach to the card insertion and removal requirement.
It therefore becomes an object of the present invention to provide an improved tool of the character described which facilitates both the insertion and extraction of such printed circuit cards.